The investigation into the tanks has revealed TEPCO’s sloppy record keeping and tank management. The firm admitted that this was because the equipment used could only read measurements up to 100 millisieverts an hour.

The readings taken near the leaking tank on Saturday, made with a more sensitive device, showed a level of 1,800 millisieverts an hour.

TEPCO also acknowledged it used to assign only two workers to visually inspect all 1,000 tanks in two hours until the leak, and none of the tanks had water gauges.

The firm has increased the patrol staff to nearly 60 and is adding other early detection measures, after it admittedly overlooked signs of leaks — radioactivity increase and workers’ exposure levels for over a month.

Japan's foreign ministry has started posting English-language information online showing that atmospheric radiation levels in Tokyo, about 225 km south of Fukushima Daiichi, are comparable with those in London and New York.

Authorities are expected to unveil emergency measures on Tuesday to deal with the crisis.

Cecilia Jamasmie, news editor at MINING.com, has over 15 years of experience in print media, TV, online media and public relations. She specializes in Corporate Social Responsibility (CSR) and the Latin American market. Cecilia has been interviewed by BBC News and CBC among others. She has also been syndicated by Forbes, Seeking Alpha and BIV. She holds a Master of Journalism (MJ) from the University of British Columbia, Canada, and she is currently based in Halifax, Nova Scotia.